Detergent formulations typically contain a number of different active components, including builders, surfactants, enzymes and bleaching agents.
Surfactants are employed to release stains and soil and to disperse the released components into the cleaning liquid. Enzymes help to remove stubborn stains of proteins, starch and lipids by hydrolyzing these components. Bleach is used to remove stains by oxidizing the components that make up these stains.
Calcium and magnesium ions have a negative effect on the removal of soils by detergent compositions. In order to negate these negative effects so called ‘builders’ (complexing agents) are commonly applied in detergent compositions.
Phosphorous based builders, such as phosphates, have been used for many years in a wide variety of detergent compositions. However, as part of an increasing trend towards environmentally friendly detergent compositions, alternative building agents have been developed and these alternative builders have found their way into commercial detergent products. Glutamic-N,N-diacetate (GLDA), methyl-glycine diacetate (MGDA) and citrate are examples of environmentally friendly builders that are used in commercial detergent products.
Liquid detergent formulations have been developed as these products offer the advantage over powdered formulations that they are easy to dose, may contain higher concentrations of active ingredients, suffer less from moisture spoilage during storage and/or are more easily dispersed into aqueous cleaning liquid. In order to provide liquid detergent compositions that deliver cleaning, spotting and filming performance similar to that of a powdered formulation it is necessary to include components that remain undissolved in the liquid product matrix. These undissolved components need to be homogeneously suspended throughout the product to guarantee a constant, optimum cleaning result. Although this may be achieved by instructing the user to shake the product before use, it is clearly preferable to provide the liquid detergent formulation in the form of a suspension that remains stable during the lifecycle of the product. This objective, however, is very difficult to achieve as suspensions demix over time because suspended particles are subject to sedimentation and creaming/floating phenomena.
WO 93/21299 describes a viscoelastic, thixotropic, liquid automatic dishwashing detergent composition comprising, by weight:                a) from 0.001% to 5% of an active detersive enzyme or enzymes;        b) from 0.1% to 10% of a viscoelastic, thixotropic thickener;        c) from 0.001% to 10% of an enzyme stabilizing system selected from the group consisting of calcium ion, propylene glycol, short chain carboxylic acid, polyhydroxyl compounds, boric acid, boronic acid and mixtures thereof;        d) from 0.01% to 40% of a detergent surfactant; and        e) sufficient pH adjusting agent, to provide said composition with a product pH between 7 and 11;wherein said composition is characterized in that it is substantially free of chlorine bleach and silicate. The Examples of WO 93/21299 describe liquid aqueous detergent compositions that contain a builder (sodium citrate), enzymes and sodium cumene sulfate.        
EP 2 431 452 describes a liquid cleaning composition comprising coloured cleaning particles as abrasives, wherein said coloured cleaning particles are selected from the group consisting of coloured nut shell particles, coloured stone particles, coloured particles derived from other plant parts, coloured wood particles and mixtures thereof, and wherein the liquid and the coloured cleaning particles have substantially same colour. The cleaning composition may comprise up to 10 wt % of chelating agents, such as aminocarboxylates. The cleaning composition may further contain from 0.01% to 50% anionic surfactants. Alkyl sulphonates, alkyl aryl sulphonates, alkyl sulphates, alkyl alkoxylated sulphate surfactants, C6-C20 alkyl alkoxylated linear or branched diphenyl oxide disulphonates are mentioned as examples of anionic surfactants.
US 2009/264329 describes a cleaner concentrate comprising:                a) one or more alkalinity sources present in an amount sufficient to provide a free alkalinity (expressed as Na2O) of greater than about 3.6 wt %, based on the total weight of the cleaner concentrate, and a total alkalinity (expressed as Na2O) of greater than about 6.1 wt %, based on the total weight of the cleaner concentrate;        b) one or more chelants present in an amount sufficient to permit a use of a water having a hardness number up to about 600 ppm (600 mg/L);        c) from about 0 wt % to about 39 wt % of one or more surfactants, based on the total weight of the cleaner concentrate; and        d) the remainder to 100 wt % of water, based on the total weight of the cleaner.        
Dicarboxymethyl glutamic acid (GLDA) and methylglycine-N—N-diacetic acid (MGDA) are mentioned as examples of chelants. The use of hydrotropes in a concentration of up to 9 wt. % of the cleaner concentrate is mentioned. Examples of hydrotropes mentioned in the US patent application include cumenesulfonic acid, sodium salt.
It is an object of the present invention to provide a pourable detergent composition in the form of a suspension that is storage stable in that it does not exhibit significant demixing during storage.